sábado, 9 de fevereiro de 2019

T127

The history of science is replete with examples of great scientific ideas that experienced hostility from prominent scientists of the time. Although jealousy might be a reason for such a response, the explanation is probably less petty. It might be simply that people, scientists among them, often have difficulty accepting new ideas that conflict with the current thinking of the day. In the ensuing essay, I will give two striking examples.

1. Dental Implants. A dental implant is a screw-like object, usually made of titanium, that is partially inserted into the jawbone where it is allowed to fuse with the bone over a span of many weeks. The immune system does not recognize the implant as a foreign object and, importantly, no soft tissue intervenes between the bone and the implant. After “osseointegration,” the titanium screws, projecting from the gums, serve to support permanent replacement teeth that look and feel like natural teeth.

We owe the dental implant to a Swede, Per-Ingvar Brånemark. In the 1950s when he was in his early twenties, he implanted a titanium device into a leg bone of a rabbit. Later he was unable to remove the device despite strenuous effort. He realized that the titanium had structurally integrated into the bone, and that this offered huge possibilities in dentistry. A major success occurred in 1963 when a patient with a congenital absence of teeth in his lower jaw received titanium implants that ultimately allowed him to speak and chew normally for the first time in over three decades. Despite such cases, the general scientific community was not prepared to accept that titanium was uniquely capable of integrating into the bone structure. Brånemark’s problems included publications from scientists who found that various non-titanium metals failed to fuse with bone and, worse, that intervening fibrous tissue created instability and infection sites. Brånemark was criticized for not being a dentist: “You are a humbug, sir” [i.e. a fraud] was shouted at him during a conference speech. He had to endure personal attacks, some of them vicious, while university funds for his research were discontinued. A popular non-technical magazine describing Brånemark’s early work only served to draw further ridicule from his colleagues. Yet Brånemark never succumbed to his detractors. Instead, he established a private dental clinic that, although not funded by the usual agencies, was supported by various industries, private donations, and patients who could afford the treatment. As his fame spread, people came to the clinic from many countries. In 2012 conferences were held in Gothenburg, Avignon, Odessa, Hamburg, and Toronto in honor of the 60th anniversary of osseointegration. Great science can be delayed (30 years in this case), and the lives of its originators can be made miserable, but eventual acceptance of valid science is inevitable.

2. Lithium as a Drug. Dr. John Cade, an Australian psychiatrist, was the first to recognize that lithium salts provide a remedy for manic-depression mental disorders. Working in simple facilities, he remarked that “These days, one would be suffocated by hospital boards, research committees, ethical committees, and heads of departments.” After testing the safety of lithium on himself, he gave lithium to ten chronically manic patients and found that they all became “more settled, tidier, less disinhibited, and less distractible.” In other words, Cade was able to control manic excitement in patients to the extent that they could be released from the hospital. In 1949 he published a paper entitled “Lithium Salts in the Treatment of Psychotic Excitement” in the Medical Journal of Australia. Cade later admitted, that a discovery “made by an unknown psychiatrist with no research training, working in a small hospital with primitive techniques and negligible equipment was not likely to be compellingly persuasive.”

Cade’s finding met great resistance, being labeled “dangerous nonsense” and “a therapeutic myth”. It did not help his cause that in 1949 cardiac patients had died from lithium chloride given in place of sodium chloride. It was difficult for many psychiatrists to accept the idea that something as simple as lithium ion could dramatically affect behavior. Although psychosis was not understood at the time, few believed that it had anything but a physical basis. Sir Aubrey Lewis and Michael Shepard, both highly respected and influential British professors in the field, entirely dismissed the possibility that mental illness could be relieved by a simple chemical. One should note that neither of these experts ever bothered testing the drug on patients themselves. Thankfully, Mogens Schou, a Danish psychiatrist, spent a lifetime, beginning in the early 1950s, campaigning for the adoption of lithium as a treatment of manic depression. It took more than twenty years for the utility of lithium to be generally recognized as a revolutionary treatment for a serious health problem.

Modifying an ingrained paradigm, never an easy task, is made even more difficult by the narrow-of-mind. Certain so-called “experts” are too short-sighted to realize that, ultimately, good science always wins out. Two current examples come from a segment of the scientific community that does not accept medical marijuana and human-caused climate change.